Geological Society. 77 



facture. Silver plates employed by us under like circumstances, 

 commenced perishing after twelve months or more of use ; they 

 crumble away in great measure, they cut apart at the surface level, 

 and they get eaten into holes throughout. 



GEOLOGICAL SOCIETY. 

 [Continued from vol. xvii. p. 44/.] 

 June 1, 1859.- — -Major-Gen. Portlock, Vice-President, in the Chair. 



The following communications were read : — 



1. " On the Sinking for Coal at the Shireoaks Colliery near 

 Worksop, Notts." By J. Lancaster, Esq., and C. C. Wright, Esq., 

 F.G.S. 



In two shafts sunk for the Duke of Newcastle on the north-west 

 side of his estate of Worksop Manor, it was found that the New Red 

 Sandstone and marl have a thickness of 54 ft., and the Permian beds 

 112 ft. ; the latter consisting of hard yellow limestone (54 ft.), blue 

 limestone and shale (20 ft.), blue shale (33 ft.), and soft gritstone, 

 probably equivalent to the "Quicksand" of the north (5 ft.). 

 Below the gritstone the coal-measures commence with 5 feet of blue 

 shale, in which there are four bands of ironstone ; another band 

 16 inches thick, lies immediately below. This iron-ore is chiefly in 

 the state of peroxide, gives an average of 42 per cent, of metallic 

 iron, and promises to be of great economical value. The first seam 

 of coal (2 feet thick and of inferior quality) was cut at a depth of 

 88 yards. Four yards below this is a compact sandstone QQ feet 

 thick. The sinking through this rock occupied 20 months ; each 

 pit made 500 gallons of water a minute, which was stopped in detail 

 by cast-iron tubing. The pressure from the gas at the bottom of this 

 thick rock was at times as high as 210 lbs. per square inch, but is 

 now about 196 lbs. per square inch. Shales, with coal-seams and 

 bands of ironstone, all thin or of inferior quality, were met with in 

 the next 170 yards. At 346 yards the first thick coal was cut, and 

 found to be 4 ft. 6 in. thick, and of good quality. This is con- 

 sidered to be the " Wathwood Coal." The " Top Hard Coal" was 

 cut at a depth of 510 yards, and found to be 3 ft. 10 in. thick : the 

 strata intervening between this and the " Wathwood Coal " were 

 found to have much the same characters and thickness as they are 

 known to have elsewhere. The sinkings were commenced in March 

 1854, and perseveringly continued until their completion on February 

 1st, 1859. Altogether 37 feet of coal were passed through; but 

 only four seams are of workable thickness. The authors of this 

 communication remark that the district appears to be remarkably 

 free from faults, that the dip decreases considerably towards the east, 

 and that the " Top Hard Coal " appears to thin out eastwardly. 



2. " Notes on the Geology of Southern Australia." By A. II. C. 

 Sclwyn, Esq., Director of tiie Geological Survey of Victoria. In a 

 Letter to Sir 11. I. Murchison, F.G.S. 



Mr. Selwyn remarked that, as to the impoverishment of auriferous 

 veins in depth, the only evidence of such being the case in Victoria 

 is the great richness of the older drifts ; for, judging from the large 



